Relay transmission method and apparatus

ABSTRACT

A relay transmission method and apparatus are provided. The method includes: configuring a subframe of a Time Division Duplex relay frame for a subframe of relay link), where the configuring the subframe of the TDD relay frame for the subframe of relay link includes: configuring a downlink subframe of the TDD relay frame for a DL subframe of relay link, and/or configuring the DL subframe of the TDD relay frame for an uplink subframe of relay link, and/or configuring a UL subframe of the TDD relay frame for the UL subframe of relay link; and performing relay transmission according to the subframe of relay link. When data is transmitted, a subframe that can be used for relay link transmission is configured, data transmission performed by using relay link complies with inherent constraints of a TDD frame structure in the prior art.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/108,716, filed on May 16, 2011, which is a continuation of U.S.patent application Ser. No, 13/018,143, filed on Jan. 31, 2011, which isa continuation of International Application No. PCT/CN2009/074506, filedon Oct. 19, 2009. The International Application claims priority toChinese Patent Application No. 200810170763.5, filed on Oct. 24, 2008and Chinese Patent Application No. 200910009900.1, filed on Feb. 2,2009. The afore-mentioned patent applications are hereby incorporated byreference in their entireties.

FIELD OF THE INVENTION

The present invention relates to the field of communicationtechnologies, and in particular, to a relay transmission method andapparatus.

BACKGROUND OF THE INVENTION

With the development of wireless communication technologies,requirements on the communication rate and communication quality areraised. Though wired transmission meets the requirements on thecommunication rate and the communication quality to some extent, thewired transmission requires an operator to lay fiber optic cables orrent cable resources, which limits the application of the wiredtransmission. The problem is effectively solved by using a relay forwireless backhauling. The implementation of the relay technology mayexpand the coverage of the cell, improve the cell capacity, and achievethe uniform cell throughput. The introduction of the relay may alsobring changes to a frame structure of an original system.

FIG. 1 is a schematic view of a relay frame structure in the prior art,where the relay frame structure is applicable to time division duplex(TDD). Referring to FIG. 1, a base station (e.g. enhanced node base(eNB)) and a Relay Node/Relay (RN) as well as the RN and a userequipment (UE) communicate through subframes 1 to 4. Subframe 1 is usedfor a downlink (DL) relay link transmission from eNB to Relay, subframe2 is used for a DL access link transmission from Relay to UE, subframe 3is used for an uplink (UL) relay link transmission from Relay to eNB,and subframe 4 is used for a UL access link transmission from UE toRelay.

During the implementation of the present invention, the inventors findthat the prior art has at least the following problem.

In an existing relay system, when data transmission is performedaccording to the TDD frame structure in the prior art, relaytransmission cannot be realized.

SUMMARY OF THE INVENTION

The present invention is directed to a relay transmission method andapparatus, so that an RN in a TDD system can perform relay transmission.

In order to achieve the above objective, an embodiment of the presentinvention provides a relay transmission method, where the methodincludes:

configuring a subframe of a TDD relay frame for a subframe of relaylink, where the configuring the subframe of the TDD relay frame for thesubframe of relay link includes: configuring a DL subframe of the TDDrelay frame for a DL subframe of relay link, and/or configuring the DLsubframe of the TDD relay frame for a UL subframe of relay link, and/orconfiguring a UL subframe of the TDD relay frame for the UL subframe ofrelay link; and

performing relay transmission according to the subframe of relay link.

An embodiment of the present invention provides a communicationapparatus, where the communication apparatus includes:

a configuring module, configured to configure a subframe of a TDD relayframe for a subframe of relay link, where the configuring the subframeof the TDD relay frame for the subframe of relay link includes:configuring a DL subframe of the TDD relay frame for a DL subframe ofrelay link, and/or configuring the DL subframe of the TDD relay framefor a UL subframe of relay link, and/or configuring a UL subframe of theTDD relay frame for the UL subframe of relay link; and

a transmitting module, configured to perform relay transmissionaccording to the subframe of relay link configured by the configuringmodule.

In the technical solutions according to the embodiments of the presentinvention, when a communication apparatus transmits data, a subframethat can be used for relay link transmission is configured, datatransmission performed by using relay link complies with inherentconstraints of a TDD frame structure in the prior art, and coverage of asystem using a TDD relay frame is expanded, thus improving thethroughput.

BRIEF DESCRIPTION OF THE DRAWINGS

To illustrate the technical solutions according to the embodiments ofthe present invention or in the prior art more clearly, the accompanyingdrawings for describing the embodiments or the prior art are givenbriefly below. Apparently, the accompanying drawings in the followingdescription are only some embodiments of the present invention, andpersons of ordinary skill in the art can derive other drawings from theaccompanying drawings without creative efforts.

FIG. 1 is a schematic view of a relay frame structure in the prior art;

FIG. 2 is a flow chart of a relay transmission method according to anembodiment of the present invention;

FIG. 3 is a schematic view of TDD with no relay transmission framestructure introduced according to an embodiment of the presentinvention;

FIG. 4 is a schematic view of a frame structure using a completesubframe as a relay link according to an embodiment of the presentinvention;

FIG. 5 is a schematic view of a frame structure using an original DLsubframe as a DL relay link and using an original UL subframe as a ULrelay link according to an embodiment of the present invention;

FIG. 6 is a schematic view of a frame structure of a system including aneNB, an RN, and a UE according to an embodiment of the presentinvention;

FIG. 7 is a schematic view of a frame structure according to anembodiment of the present invention;

FIG. 8 is a schematic view of another frame structure according to anembodiment of the present invention;

FIG. 9 is a schematic view of another frame structure according to anembodiment of the present invention;

FIG. 10 is a schematic view of another frame structure according to anembodiment of the present invention;

FIG. 11 is a schematic view of another frame structure according to anembodiment of the present invention;

FIG. 12 is a schematic view of another frame structure according to anembodiment of the present invention;

FIG. 13 is a schematic view of another frame structure according to anembodiment of the present invention;

FIG. 14 is a schematic view of another frame structure according to anembodiment of the present invention;

FIG. 15 is a schematic view of another frame structure according to anembodiment of the present invention; and

FIG. 16 is a schematic structural view of a communication apparatusaccording to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The technical solutions of the present invention will be clearly andcompletely described in the following with reference to the accompanyingdrawings. It is obvious that the embodiments to be described are only apart rather than all of the embodiments of the present invention.Persons of ordinary skill in the art can derive other embodiments fromthe embodiments given herein without making any creative effort, and allsuch embodiments are covered in the protection scope of the presentinvention.

FIG. 2 is a flow chart of a relay transmission method according to anembodiment of the present invention, and as shown in FIG. 2, the relaytransmission method includes the following steps.

In step S201, a subframe of a TDD relay frame is configured for asubframe of relay link.

The configuring the subframe of the TDD relay frame for the subframe ofrelay link includes: configuring a DL subframe of the TDD relay framefor a DL subframe of relay link, and/or configuring the DL subframe ofthe TDD relay frame for a UL subframe of relay link, and/or configuringa UL subframe of the TDD relay frame for the UL subframe of relay link.

In step S202, relay transmission is performed according to the subframeof relay link.

When the relay transmission is performed according to the configuredsubframe of relay link, if the DL subframe of the relay frame is used asthe UL subframe of relay link or the DL subframe of relay link, thefirst N orthogonal frequency division multiplexing (OFDM) symbols of theDL subframe are configured for access link transmission between a RN anda UE under the RN or between an eNB and a UE under the eNB, and areconfigured to send a DL reference signal, or a DL reference signal andcontrol signaling. Other OFDM symbols of the DL subframe are used forrelay link transmission and/or a guard period (GP); that is to say, thetime other than the first N OFDM symbols of the DL subframe is used forthe relay link transmission and/or the GP.

The DL subframe includes M OFDM symbols, M and N are natural numbers,and N is smaller than M.

The solution provided by the embodiment of the present invention can beapplied to systems such as long term evolution (LTE), LTE advanced(LTE-A), all versions of the LTE (such as Rel-8, Rel-9, and Rel-10),world interoperability for microwave access (WiMax), and ultra widebandwireless communication (UWB).

For example, in an LTE/LTE-A system, a communication apparatus transmitsdata according to a TDD relay frame. Each frame of the TDD relay frameincludes 10 subframes, the length of each frame is 10 ms, and the lengthof each of the subframes is 1 ms. The LTE/LTE-A TDD relay frame includesa subframe of relay link, an access link subframe, and a GP. Thesubframe of relay link occupies one or more subframes. The access linksubframe occupies one or more subframes. The GP occupies a part of aspecial LTE/LTE-A TDD subframe, or the GP occupies a part of thesubframe of relay link. Communication between an eNB and a UE served bythe eNB is performed according to the subframe of relay link; and/orcommunication between an eNB and an RN is performed according to thesubframe of relay link; and/or communication between an RN and a UEserved by the RN is performed according to the subframe of relay link.When the eNB or the RN performs relay transmission, TDD frames with thesame ratio of the DL subframes to the UL subframes may be used, orframes of the same configuration may be used. The GP specificallyincludes: a receive-transmit state transition time and an idle time. Thereceive-transmit state transition time is a receive-transmit statetransition time of the eNB and/or a receive-transmit state transitiontime of the RN. The GP is an integer multiple of a sampling time, or,the GP is a time when the number of sampling points is a divisor of thenumber of Fourier transform points and the number of the sampling pointsis the number of the Fourier transform points/2^n, where n is a naturalnumber. Or, the GP may also be obtained from at least one among a cyclicprefix of the OFDM symbol, the OFDM symbol, and the subframe. Or, the GPis adjusted in signaling by a transmitter and a receiver.

For all the embodiments of the present invention, in all theaccompanying drawings, D represents a subframe for DL, U represents asubframe for UL, and S represents a special subframe in an LTE/LTE-A TDDsystem. The special subframe includes a downlink pilot timeslot (DwPTS),an uplink pilot timeslot (UpPTS), and a GP. Similarly, in all thetables, D also represents a DL subframe, U represents a UL subframe, andS represents a special subframe for a DwPTS, an UpPTS, and a GP.

In a TDD relay frame structure, if a UE sends a Physical Uplink SharedChannel (PUSCH) in subframe n, the UE receives a physical hybridautomatic repeat request (HARQ) indication channel (PHICH) in a k^(th)subframe after subframe n, that is, DL subframe n+k, where values of nand k (values of k are as shown in configuration rows 0 to 6) areprovided in Table 1.

TABLE 1 TDD UL/DL Subframe n Configuration 0 1 2 3 4 5 6 7 8 9 0 4 7 6 47 6 1 4 6 4 6 2 6 6 3 6 6 6 4 6 6 5 6 6 4 6 6 4 7

For example, in Table 1, for a 3rd subframe (n=3) in a frame, in the 0thconfiguration row, k is correspondingly equal to 7; a UE sends a PUSCHin the 3rd subframe, and receives a PHICH in a 0th subframe (3+7) of anext frame. For another configuration, for example, in the 1stconfiguration row, k is correspondingly equal to 6; the UE sends a PUSCHin the 3rd subframe, and receives a PHICH in a 9th subframe (3+6).

In the TDD relay frame structure, if the UE receives a physical downlinkshared channel (PDSCH) in subframe n, the UE sends anacknowledgement/negative acknowledgement (ACK/NACK) in subframe n+k,where values of n and k (values of k are as shown in configuration rows0 to 6) are provided in Table 2.

TABLE 2 Subframe n Configuration 0 1 2 3 4 5 6 7 8 9 0 4 6 — — — 4 6 — —— 1 7 6 — — 4 7 6 — — 4 2 7 6 — 4 8 7 6 — 4 8 3 4 11 — — — 7 6 6 5 5 412 11 — — 8 7 7 6 5 4 5 12 11 — 9 8 7 6 5 4 13  6 7 7 — — — 7 7 — — 5

For example, in Table 2, for a 3^(rd) subframe (n=3) in a frame, in the2^(nd) configuration row, k is correspondingly equal to 4; a UE receivesa PDSCH in the 3^(rd) subframe, and sends an ACK/NACK in a 7^(th)subframe (3+4). For another configuration, for example, in the 5^(th)configuration row, k is correspondingly equal to 9; the UE receives aPDSCH in the 3^(rd) subframe of UL, and sends an ACK/NACK in a 2^(nd)subframe (3+9) of a next frame.

In the TDD Relay frame structure, if the UE receives a UL grant/PHICH insubframe n (transfers UL data/or ANK/NACK of a UL PUSCH), the UE sendsthe PUSCH in subframe n+k. Correspondence relations between the ULgrant/PHICH and the PUSCH are as shown in Table 3 (in the followingtables, the UL grant can be replaced with the PHICH, which is notindicated again hereinafter).

TABLE 3 DL/UL ratio TDD UL/DL UL grant VS. Subframe index nConfigurafion PUSCH 0 1 2 3 4 5 6 7 8 9 0 1:3 D S U U U D S U U U ULgrant VS. PUSCH G0-4 G1-6 G5-4 G6-6 G0-7 G1-7 G5-7 G6-7 1 2:2 D S U U DD S U U D UL grant VS. PUSCH G1-6 G4-4 G6-6 G9-4 2 3:1 D S U D D D S U DD UL grant VS. PUSCH G3-4 G8-4 3 6:3 D S U U U D D D D D UL grant VS.PUSCH G0-4 G8-4 G9-4 4 7:2 D S U U D D D D D D UL grant VS. PUSCH G8-4G9-4 5 8:1 D S U D D D D D D D UL grant VS. PUSCH G8-4 6 3:5 D S U U U DS U U D UL grant VS. PUSCH G0-7 G1-7 G5-7 G6-7 G9-5

In Table 3, G represents a grant (scheduling UL data signaling), Gn-krepresents that when a UE receives a UL grant in subframe n, the UEsends a PUSCH in subframe n+k. For example, in a 1st subframe, when aratio of DL subframes to UL subframes is 2:2, a correspondence relationbetween the UL grant and the PUSCH is G1-6. That is to say, when the UEreceives a UL grant in the 1st subframe, the UE sends a PUSCH in a 7thsubframe (1+6).

FIG. 3 is a schematic view of TDD with no relay transmission framestructure introduced according to an embodiment of the presentinvention. Pattern A represents a time unit of DL and UL communicationperformed by an eNB and a UE_eNB (a UE served by the eNB). In FIG. 3,the time unit is a subframe (the length of one subframe is 1 ms). EachDL subframe is configured for DL communication from eNB to UE_eNB, andeach UL subframe is configured for UL communication from UE_eNB to eNB.When a frame structure for relay transmission is introduced into theTDD, as shown in FIG. 4, which is a schematic view of a frame structureusing a complete subframe for a relay link according to an embodiment ofthe present invention, in FIG. 4, for the DL, one or more subframes maybe used for relay link between an eNB and an RN, and similarly, for theUL, one or more subframes may be used for relay link from the RN to theeNB. When the relay link are exclusively used for the UL and DLcommunication between the eNB and the RN, the relay link are calleddedicated relay link. When the relay link are used for both thecommunication between the eNB and the RN and the communication betweenthe eNB and the UE_eNB, the relay link are called non-dedicated relaylink. The number of the subframes used for the relay link of the UL maybe the same as or different from the number of the subframes used forthe relay link of the DL. In FIG. 4, the DL relay link and the UL relaylink of the RN may occupy a complete subframe of relay link, or occupy apart of the subframe of relay link excluding a GP. A frame structure forrelay transmission is introduced into the TDD, as shown in FIG. 5, whichis a schematic view of a frame structure using an original DL subframefor a DL relay link and using an original UL subframe for a UL relaylink according to an embodiment of the present invention. In FIG. 5,patterns A represent communication link between an eNB and a UE_eNB,between the eNB and an RN, and between the RN and a UE_RN, which can beconfigured to transmit channels used by the LTE such as a controlchannel, a data channel, a reference signal, a synchronization channel,or a broadcast channel. In order to perform channel interpolationbetween time-domain DL subframes, first several (1, 2, 3, or 4) OFDMsymbols of a subframe of the DL relay link, indicated by patterns B inFIG. 5, are used for an access link between the eNB and the UE_eNB andan access link between the RN and the UE_RN. The access link (patternsB) is configured to send a reference signal, a control channel, a PHICH,or a Physical Control Format Indicator Channel (PCFICH). For example,only the DL reference signal is sent, or the DL reference signal and thecontrol signaling such as a Physical Downlink Control Channel (PDCCH),the PHICH, or the PCFICH are sent. In an LTE/LTE-A TDD system, a DLsubframe of pattern B may be a Multimedia Broadcast multicast serviceover a Single Frequency Network (MBSFN) subframe, and in this case,pattern B is equivalent to a unicast part of the MBSFN subframe, and isconfigured to, for example, send a DL reference signal, or a DLreference signal and control signaling such as a control channel, aPHICH, or a PCFICH, on an access link between an RN and a UE_RN. Therest of the MBSFN subframe is used for DL communication between an eNBand the RN and a GP, or is also used for communication between the eNBand a UE_eNB at the same time. The subframe of the eNB with pattern Bmay be a normal subframe, and in this case, pattern B is equivalent to acontrol channel part in the front of the normal subframe. The referencesignal is sent in pattern B, so that channel estimation interpolationcan be performed between the sent reference signal and a referencesignal of a previous subframe, thus further improving the channelestimation performance. A frame structure for relay transmission isintroduced into the TDD relay frame structure, as shown in FIG. 6, whichis a schematic view of a frame structure of a system including an eNB,an RN, and a UE according to an embodiment of the present invention.Patterns A represent link through which the eNB and the UE_eNB performDL and UL communication, and link through which the RN and the UE_RNperform DL and UL communication. Pattern B represents a DL relay linkfrom the eNB to the RN, which can be configured to send a controlchannel, a data channel, or a reference signal, and the control channel,the data channel, or the reference signal may also be sent to the UE_eNBat the same time. Patterns C represent DL access link, respectively fromthe eNB to the UE_eNB and from the RN to the UE_RN, and configured totransmit channels such as a PHICH, a UL grant, a PCFICH, or a DLreference signal. Occupied first several (1, 2, 3, or 4) OFDM symbols ofa subframe with pattern C are used for the DL access link from the eNBto the UE_eNB and the DL access link from the RN to the UE_RN, andconfigured to transmit information including control signaling such as aPHICH, a UL grant, and a PCFICH, and/or a DL reference signal. Pattern Erepresents a corresponding part of an original DL subframe from the eNBto the UE_eNB transmission after being converted to a UL from the RN tothe eNB transmission, that is, the subframe of pattern E, so that theoriginal DL subframe is used as a UL subframe of relay link. In theLTE/LTE-A TDD system, the DL subframe of pattern E may be an MBSFNsubframe, pattern C is equivalent to a unicast part of the MBSFNsubframe, and is configured to send a DL reference signal, and/orcontrol signaling such as a PDCCH, a PHICH, or a PCFICH on an accesslink between the eNB and the UE_eNB and an access link between the RNand the UE_RN. The rest of the MBSFN subframe is used for ULcommunication between the eNB and the RN and a GP. Pattern D representsa GP, and the GP includes a receive-transmit state transition time andan idle time. The receive-transmit state transition time is areceive-transmit state transition time of the eNB and/or areceive-transmit state transition time of the RN. The length of the GPmay be an integer multiple of a sampling time, or be equal to[N/(2^n)×the sampling time], where N is the number of Fourier transformpoints used in the LTE/LTE-A system, n is a natural number such as 1, 2,3, . . . , and 2^n≦N. Pattern E represents a UL relay link from the RNto the eNB.

In FIG. 6, pattern A of the UL part may be used for a UL access link fortransmission from the UE_eNB to the eNB, and may also be used for a ULaccess link for transmission from the UE_RN to the RN. Pattern A of theDL part may be used for a DL access link for transmission from the eNBto the UE_eNB, and may also be used for a DL access link fortransmission from the RN to the UE_RN. Pattern B of the DL part may beused for a DL relay link for transmission from the eNB to the RN, andmay also be used for a mixed link of a DL access link for transmissionfrom the eNB to the RN and a DL access link for transmission from theeNB to the UE_eNB. Pattern B is used for a relay link from the eNB tothe RN, and if the throughput required by the relay link does not needto use all the resources of pattern B, pattern B may also transmit oneor all of a data channel, a control channel, and a reference signalchannel from the eNB to the UE_eNB at the same time. Pattern Drepresents a time during which the eNB and/or the RN does not transmitdata, and may be used as the receive-transmit state transition time ofthe eNB and/or the receive-transmit or transmit-receive transition timeof the RN, or an idle time. As shown in FIG. 6, pattern D may also existbetween pattern C of the RN and pattern E of the RN, and pattern Ddepends on whether a propagation time between the eNB and the RN meetsthe transmit-receive transition time of the eNB. When the propagationtime between the eNB and the RN is longer than the receive-transmittransition time, the first pattern D of the eNB in the subframe of theUL is required to be longer than the receive-transmit transition time.When the propagation time is shorter than the receive-transmittransition time, pattern D is required to be added between pattern C ofthe RN and pattern E of the RN, and the length of the time (pattern D)equals a difference between a transmit-receive transition time of theeNB and a transmission time from the RN to the eNB. That is to say, thetime length of pattern D may vary in different positions, but pattern Dis placed within the subframe of the relay link. The above transitiontime or transmission time (for example, pattern D in FIG. 6) may also beadjusted by a transmitter and a receiver in signaling, for example,regularly, and not indicated in the frame structure.

In view of the above, in this embodiment, when a communication apparatustransmits data, a subframe that can be used for relay link transmissionis configured, data transmission performed by using relay link complieswith inherent constraints of Rel-8 of the LTE system, and coverage ofthe LTE system using the LTE/LTE-A TDD relay frame is expanded, thusimproving the throughput.

In all of the embodiments of the present invention, the ratio of the DLsubframes to the UL subframes is the ratio of the DL subframes to the ULsubframes when the relay is not introduced. After the relay isintroduced, the ratio of the DL subframes to the UL subframes maychange, which depends on actual applications.

An embodiment of the present invention provides a frame structure, wherea ratio of LTE/LTE-A TDD relay frames is a ratio of DL subframes to ULsubframes being 6:3. In this embodiment, a correspondence relationbetween a UL grant and a PUSCH is shown in Table 4. For example, if a UEreceives a UL grant sent to the UE in subframe 0, the UE shall send aPUSCH in a corresponding subframe 4. If the UE receives a UL grant sentto the UE in subframe 8/9, the UE shall send a PUSCH in a correspondingsubframe 2/3 of a next frame.

TABLE 4 DL/UL ratio TDD UL/DL UL grant VS. Subframe index nConfiguration PUSCH 0 1 2 3 4 5 6 7 8 9 3 6:3 D S U U U D D D D D ULgrant VS. PUSCH G0-4 G8-4 G9-4 PUSCH Position

A correspondence relation between a PHICH and a UL ACK/NACK is shown inTable 5. In Table 5, patterns being the same have a correspondingrelation. For example, when the UE sends the PUSCH in subframe 4,accordingly, the UE sends the PHICH in the position of subframe 0 of anext frame; when a PDSCH is sent in subframe 0, and the UL ACK/NACK issent in subframe 4 of this frame.

TABLE 5 TDD UL/DL UL subframe index n Configuration 0 1 2 3 4 5 6 7 8 93 6 6 6 PUSCH PHICH position 6 6 6 DL Subframe index n Configuration 0 12 3 4 5 6 7 8 9 3 4 11 — — — 7 6 6 5 5 PDSCH ULACK position 11  6 4 7 55 6

In an LTE TDD frame structure, subframes 0, 1, 5, and 6 are configuredto send a Primary Broadcast Channel (P-BCH), a Dynamic Broadcast Channel(D-BCH), or a Primary/Secondary Synchronization Channel (P/S-SCH). Inthe frame structure, subframes 0, 1, 5, and 6 cannot be configured for aDL relay link, and as seen from Table 5, available DL relay subframescan only be subframes 7, 8, and 9. From Table 5, it can also be seenthat subframes 0, 1, 5, and 6 respectively correspond to subframes 2 and4 in where UL ACK/NACK is transmitted. Therefore, subframes 2 and 4cannot be used for a UL relay link. As seen from Table 5, only subframe3 can be used for a UL relay link. The UE receives the PDSCH insubframes 7 and 8. Accordingly, the UE is required to send the ULACK/NACK in subframe 3 (7+6 or 8+5) of a next frame, and meanwhilesubframes 7 and 8 may be used for a DL relay link. From Table 4, it canbe seen that a PUSCH of subframe 2 of a next frame is required to besent in subframe 8. If subframe 8 is not configured for sending a ULgrant, the PUSCH cannot be sent in subframe 2, thus wasting theresources. Therefore, first several (1, 2, 3, or 4) OFDM symbols ofsubframe 8 can be configured for transmission of an access link. Throughthe first several symbols of subframe 8, control signaling such as a DLcontrol channel, a PCFICH, or a PHICH, and/or a reference signal can besent between the eNB and the UE_eNB, and the control signaling such asthe DL control channel, the PCFICH, or the PHICH, and/or the referencesignal can be sent between the RN and the UE_RN. As can be seen fromTable 4, when the UL grant is sent in the subframe 9 of a previousframe, the PUSCH is required to be sent in subframe 3 of this frame, andsubframe 3 is used for a relay link between the RN and the eNB; and whenthe PUSCH is sent in subframe 3, the RN cannot receive the data sent bythe UE_RN, so that in the above configuration, subframe 9 of theprevious frame cannot be configured for sending the UL grant controlchannel of the PDCCH to schedule UL data. Therefore, one or more amongsubframes 3, 7, 8, and 9 may be configured for DL subframes of relaylink, and the rest subframes may be used as UL subframes of relay link.The number of the subframes that are used as the UL subframes of relaylink is greater than or equal to 1, and subframe 3 can only be used asthe UL subframe of relay link.

FIG. 7 is a schematic view of a frame structure according to anembodiment of the present invention, where a ratio of DL subframes to ULsubframes of an original LTE system including relay link and access linkis 6:3. In the frame structure, a set of subframes that are configuredfor the relay link is [3, 7, 8]. In FIG. 7, a D-relay link (Psubframe)and a U-relay link (Psubframe) are a relay time used for communicationbetween an RN and an eNB, the D-relay link represents a DL relay time ofthe communication between the RN and the eNB, and the U-relay linkrepresents a UL relay time of the communication between the RN and theeNB. A communication part of the UL between the RN and the eNB may alsobe configured to transmit a UL control channel, a data channel, and areference signal between a UE and the eNB. In FIG. 7, patterns ABrepresent access link for the eNB and a UE_eNB and access link for theRN and a UE_RN, which can be configured to send the reference signal, aDL control channel, a PCFICH, or a PHICH. For example, only thereference signal is sent, or the reference signal and control signalingsuch as the DL control channel, the PCFICH, or the PHICH are sent.Patterns AC of subframes of the relay link (Psubframe) may be used as areceive-transmit or transmit-receive transition time of the RN, and idletime such as a transmission time delay between the eNB and the RN. Inall of the accompanying drawings of the embodiments of the presentinvention, all patterns AB being the same as patterns AB in FIG. 7represent access link for the eNB and the UE_eNB and access link for theRN and the UE_RN; and all patterns AC being the same as patterns AC inFIG. 7 represent a receive-transmit or transmit-receive transition timeof the RN, and idle time such as a transmission time delay between theeNB and the RN, which will not be repeated hereinafter.

FIG. 8 is a schematic view of another frame structure according to anembodiment of the present invention, where a ratio of DL subframes to ULsubframes of an original LTE system including relay link and access linkis 6:3. In the frame structure, a set of subframes that are configuredfor the relay link is [3, 7, 8, 9]. That is to say, subframe 3 is usedfor transmission from RN to eNB, and subframes 7, 8, and 9 are used fortransmission from eNB to RN. That is, subframe 3 is configured for a ULsubframe of relay link, and subframes 7, 8, and 9 are configured for DLsubframes of relay link. The first several OFDM symbols of subframes 7,8, and 9 may be configured to send control channels for the access link,for example, control signaling such as a UL grant, a PHICH, or a PCFICH,and/or a reference signal. When a UL subframe is used for the DL of arelay link, since communication between an RN and an eNB may causesserious interference on communication between a UE_eNB and an eNB of aneighbor cell, the feasibility of this action is low. When a DL subframeis used for the UL of the communication between the RN and the eNB, theinterference on a UL direction from the eNB of the neighbor cell isrelatively weaker than that when the UL subframe is used for the DLrelay link, so that the DL subframe may be used for the UL relay link.As can be seen from Table 4, a UL grant sent in subframe 9 of a previousframe corresponds to a PUSCH sent in subframe 3. If subframe 9 ischanged into the UL, no UL grant exists in subframe 3, a PHICH is notneeded to sent in subframe 9, subframe 7 may be configured fortransmission from eNB to RN, that is, the DL of the relay link, andsubframe 9 may be configured for transmission from RN to eNB, that is,the UL of the relay link. In order not to waste resources of subframe 3,first several OFDM symbols of subframe 9 may be configured to sendcontrol channels, for example, control signaling such as the UL grant ofsubframe 3 of a next frame, the PHICH, or the PCFICH, and/or thereference signal. The sending of the reference signal also facilitateschannel estimation interpolation between access link subframes.

FIG. 9 is a schematic view of another frame structure according to anembodiment of the present invention, where a ratio of DL subframes to ULsubframes of an original LTE system including relay link and access linkis 6:3. In the frame structure, a set of subframes that are configuredfor the relay link is [7, 9]. Subframe 7 may be configured for a DLsubframe of relay link, and subframe 9 may be configured for a ULsubframe of relay link; or in a reversed manner, subframe 7 may beconfigured for a UL subframe of relay link, and subframe 9 may beconfigured for a DL subframe of relay link. Specifically, when subframes0, 1, 2, 3, 4, 5, 6, and 8 are respectively used for UL and DL accesslink between an eNB and a UE_eNB, and UL and DL access link between anRN and a UE_RN. The eNB and the UE_eNB send a control channel, a datachannel, and a reference signal channel to each other on the accesslink. On the DL access link, the eNB further sends a broadcast channeland a synchronization channel. The RN and the UE_RN send a controlchannel, a data channel, and a reference signal channel to each other onthe access link. On the DL access link, the RN further sends a broadcastchannel and a synchronization channel. In the subframe of the relaylink, for example, subframe 9 in the frame structure shown in FIG. 9,for the eNB, the first 1 to 4 OFDM symbols of the subframe are used bythe eNB to send the reference signal and/or control channel to a UEunder the eNB, an immediate following part is a transmit-receivetransition time of the eNB, a next following part is a relay link(Psubframe) time, and a still next following part is a receive-transmittransition time of the eNB. For the RN, the first 1, 2, 3, or 4 OFDMsymbols of the subframe are used by the eNB and the RN to send controlsignaling such as a control channel, a PHICH, and a PCFICH, and/or areference signal to an UE under the eNB and an UE under the RNrespectively. The sending of the reference signal also facilitateschannel estimation interpolation between access link subframes. Animmediate following part is a relay link Psubframe time of the RN, whichis followed by a transmit-receive transition time of the RN. Thetransition time takes into account a time in which the eNB caneffectively receive a relay area Psubframe. According to requirements onservices and system capacity, the Psubframe may exist in multiplesubframes, and is a part of the subframe. In addition, in the framestructure with the ratio of the DL subframes to the UL subframes of theoriginal LTE system including the relay link and the access link being6:3, a set of subframes that are configured for the relay link is [7,8]. Subframe 7 may be configured for a DL subframe of relay link, andsubframe 8 may be configured for a UL subframe of relay link; or in areversed manner, subframe 7 may be configured for a UL subframe of relaylink, and subframe 8 may be configured for a DL subframe of relay link.Or, one or more among subframes [3, 7, 8, 9] are configured for DLsubframes of relay link, the rest subframes are used as UL subframes ofrelay link, the number of the subframes used as the UL subframes ofrelay link is greater than or equal to 1, and subframe 3 can only beused as the UL subframe of relay link.

It can be clearly seen that, in this embodiment, in the frame structurewith the ratio of the DL subframes to the UL subframes being 6:3,subframes are configured for relay link transmission, data transmissionperformed by using the relay link complies with inherent constraints ofRel-8 of the LTE system with the ratio being 6:3, and coverage of anLTE/LTE-A system using an LTE/LTE-A TDD relay frame is expanded, thusimproving the throughput.

An embodiment of the present invention provides a frame structure, wherea ratio of LTE/LTE-A TDD frames is a ratio of DL subframes to ULsubframes being 3:1. In this embodiment, a correspondence relationbetween a UL grant and a PUSCH is shown in Table 6. For example, if a UEreceives a UL grant of a PDCCH in subframe 3, the UE sends a PUSCH insubframe 7 of this frame, and if the UE receives the UL grant insubframe 8, the UE sends the PUSCH in subframe 2 of a next frame.

TABLE 6 DL/UL ratio TDD UL/DL UL grant VS. Subframe index nConfiguration PUSCH 0 1 2 3 4 5 6 7 8 9 2 3:1 D S U D D D S U D D ULgrant VS. PUSCH G3-4 G8-4 PUSCH Position

A correspondence relation between a PHICH and a UL ACK/NACK is shown inTable 7. In Table 7, patterns being the same have a correspondingrelation.

TABLE 7 TDD UL/DL UL subframe index n Configuration 0 1 2 3 4 5 6 7 8 92 6 6 PHICH position 6 6 Subframe n Configuration 0 1 2 3 4 5 6 7 8 9 27 6 — 4 8 7 6 — 4 8 UL ACK/ 8 7 NACK position 7 6 6 4 4 8

In Table 7, subframes 0, 1, 5, and 6 are configured to send a broadcastchannel and a synchronization channel, and are not configured for relaylink. A UL ACK/NACK may be received in subframes 2 and 7 from the abovesubframes (a previous frame of this frame). When data is sent insubframes 2 and 7 of this frame, a PHICH is sent in subframe 8correspondingly; and when data is sent in subframe 7 of a previousframe, a PHICH is sent in subframe 3 of this frame. Subframes 4 and 9are required to be used for the DL and UL of the relay link. That is tosay, one or more among subframes [3, 4, 8, and 9] may be configured forDL subframes of relay link, and the rest are used as UL subframes ofrelay link. The number of the subframes that are used as the ULsubframes of relay link is greater than or equal to 1. Specifically,subframe 4 may be used for the DL of the relay link, that is, from theeNB to the RN; and subframe 9 may be used for the UL of the relay link,that is, from the RN to the eNB. Or in a reversed manner, subframe 4 isused as a UL subframe of relay link, and subframe 9 is used as a DLsubframe of relay link.

FIG. 10 is a schematic view of another frame structure according to anembodiment of the present invention, where subframe 4 may be used forthe DL of a relay link transmission, that is, from eNB to RN, andsubframe 9 may be used for the UL of a relay link transmission, that is,from RN to eNB. Patterns AC in subframes 4 and 9 represent atransmit-receive transition time and a receive-transmit transition timeof the RN. The length may be adjusted according to a distance from theeNB to the RN and an actual receive-transmit state transition time.Alternatively, when an original DL subframe is used as a relay subframe,first several OFDM symbols of the subframe may be used for access linktransmission from eNB to UE and access link transmission from RN to UE,control signaling such as a DL control channel, a PCIFICH, or a PHICH,and/or a reference signal. The insertion of the reference signalfacilitates channel estimation interpolation performed between areference signal of a previous access link subframe and the referencesignal, and also improves the channel estimation performance.

It can be clearly seen that, in this embodiment, in the frame structurewith the ratio of the DL subframes to the UL subframes being 3:1,subframes are configured for relay link transmission, data transmissionperformed by using the relay link complies with inherent constraints ofRel-8 of the LTE system with the ratio being 3:1, and coverage of anLTE/LTE-A system using an LTE/LTE-A TDD relay frame is expanded, thusimproving the throughput.

An embodiment of the present invention provides a frame structure, wherea ratio of LTE/LTE-A TDD frames is a ratio of DL subframes to ULsubframes being 7:2. In this embodiment, a correspondence relationbetween a PHICH and a UL ACK/NACK is shown in Table 8, and acorrespondence relation of a UL grant and a PUSCH is shown in Table 9.

TABLE 8 TDD UL/DL UL subframe index n Configuration 0 1 2 3 4 5 6 7 8 9PUSCH 6 6 PHICH position 6 6 Subframe n Configuration 0 1 2 3 4 5 6 7 89 PDSCH 12 11 — — 8 7 7 6 5 4 ULACK position 12  7 11  6 8 5 7 4

TABLE 9 TDD UL/DL DL/UL ratio Subframe index n Configuration UL grantVS. PUSCH 0 1 2 3 4 5 6 7 8 9 4 7:2 D S U U D D D D D D UL grant VS.PUSCH G8-4 G9-4

As can be seen from Table 8 and Table 9, subframes 0, 1, 5, and 6 cannotbe used for relay link, and the UL ACK/NACK corresponding to subframes0, 1, 5, and 6 is sent in two UL subframes. Therefore, the DL subframesare configured for the DL of the relay link and the UL of the relaylink, respectively. That is to say, one or more among subframes [4, 7,8, 9] may be configured for DL subframes of relay link, and the rest maybe used as UL subframes of relay link. The number of the subframes thatare used as the UL subframes of relay link is greater than or equalto 1. FIG. 11 is a schematic view of another frame structure accordingto an embodiment of the present invention, where the frame structureincludes relay link and access link. A DL subframe 4 may be configuredfor transmission from eNB to RN, and DL subframe 7 may be configured fortransmission from RN to eNB; or, subframe 4 is used as a UL subframe ofrelay link, and subframe 7 is used as a DL subframe of relay link.

It can be clearly seen that, in this embodiment, in the frame structurewith the ratio of the DL subframes to the UL subframes being 7:2,subframes are configured for relay link transmission, data transmissionperformed by using the relay link complies with inherent constraints ofRel-8 of the LTE system with the ratio being 7:2, and coverage of anLTE/LTE-A system using an LTE/LTE-A TDD relay frame is expanded, thusimproving the throughput.

An embodiment of the present invention provides a frame structure, wherea ratio of LTE/LTE-A TDD frames is a ratio of DL subframes to ULsubframes being 2:2. Similarly, according to inherent constraints of LTER-8 of the ratio, DL subframes [0, 1, 5, 6] and UL subframes [2, 7] arenot suitable for relay link. Therefore, one or more among subframes [3,4, 8, 9] may be configured for DL subframes of relay link, and the restsubframes are used as UL subframes of relay link. The number of thesubframes that are used as the UL subframes of relay link is greaterthan or equal to 1, and subframe 3 and subframe 8 can only be used as ULsubframes of relay link.

FIG. 12 is a schematic view of another frame structure according to anembodiment of the present invention. In this embodiment, when two pairsof relay link exist in 10 ms, a relay receive-transmit transition timeis placed in a subframe of the relay link. Since the value may beadjusted according to actual requirements, such as a distance from an RNto an eNB, and a receive-transmit/transmit-receive transition time, therelay receive-transmit transition time may also be placed in adjacentpositions of the UL and DL relay subframes. Subframes of the relay linkPsubframe are subframes [3, 4, 8, 9].

The above 10 ms frame structure includes 2 pairs of relay link, and mayalso include only one pair of relay link. FIG. 13 is a schematic view ofanother frame structure according to an embodiment of the presentinvention, where a receive-transmit transition time of the relay linkmay be indicated in the frame structure implicitly, that is, byinforming an RN transmission time or an end time of receiving an eNB,and the receive-transmit transition time of the relay link may also beidentified by areas AC in the figure explicitly. In the figure, a set is[3, 9], that is, subframe 9 is used for transmission from eNB to RN, andsubframe 3 is used for transmission from RN to eNB. Besides, when theset is [4, 8], subframe 4 is configured for a DL subframe of relay link,and subframe 8 is configured for a UL subframe of relay link; and whenthe set is [3, 4, 8, 9], subframes 4 and 9 are configured for DLsubframes of relay link, and subframes 3 and 8 are configured for ULsubframes of relay link.

It can be clearly seen that, in this embodiment, in the frame structurewith the ratio of the DL subframes to the UL subframes being 2:2,subframes are configured for relay link transmission, data transmissionperformed by using the relay link complies with inherent constraints ofRel-8 of the LTE system with the ratio being 2:2, and coverage of anLTE/LTE-A system using an LTE/LTE-A TDD relay frame is expanded, thusimproving the throughput.

FIG. 14 is a schematic view of another frame structure according to anembodiment of the present invention, where a ratio of LTE/LTE-A TDDframes is a ratio of DL subframes to UL subframes being 3:5. As shown inFIG. 14, a set [4, 9] is subframes of relay link Psubframe. Sub-frame 4is a UL for RN->eNB, subframe 9 is a DL for eNB->RN, and a controlchannel similar to the above exists in subframe 9. Since a subframe ofrelay link is near to a UL-DL transition position of an original system,and the original system has a GP, the GP may not be shown in the figure.Patterns AB in the front of subframes 9 respectively represent accesslink transmission from eNB to UE_eNB and access link transmission fromRN to UE_RN, and the length thereof may be one among 1, 2, 3, or 4symbols, so that a reference signal can be sent, or a reference signaland control signaling such as a DCCH, a PHICH, or a PCFICH can be sent.

It can be clearly seen that, in this embodiment, in the frame structurewith the ratio of the DL subframes to UL subframes being 3:5, subframesare configured for relay link transmission, data transmission performedby using the relay link complies with inherent constraints of Rel-8 ofthe LTE system with the ratio being 3:5, and coverage of an LTE/LTE-Asystem using an LTE/LTE-A TDD relay frame is expanded, thus improvingthe throughput.

An embodiment of the present invention provides a frame structure, wherea ratio of LTE/LTE-A TDD frames is a ratio of DL subframes to ULsubframes being 8:1. Similarly, according to inherent constraints of LTER-8 of the ratio, DL subframes [0, 1, 5, 6] and UL subframe [2] are notsuitable for relay link. Therefore, one or more among subframes [3, 4,7, 8, 9] may be configured for DL subframes of relay link, and the restsubframes are used as UL subframes of relay link. The number of thesubframes that are used as the UL subframes of relay link is greaterthan or equal to 1.

FIG. 15 is a schematic view of another frame structure according to anembodiment of the present invention, where a ratio of LTE/LTE-A TDDframes is a ratio of DL subframes to UL subframes being 8:1. DL subframe3 is configured for a UL relay link from an RN to an eNB, DL subframes[7, 8, 9] are configured for a DL relay link from the eNB to the RN, andall of DL subframes [7, 8, 9] are MBSFN subframes. For the DL subframes,the very first, or first two, or first three OFDM symbols of each of thesubframes are a unicast part, and the rest of the time is for relay linktransmission between the RN and the eNB, and a GP (indicated by patternsAC). The unicast of DL subframe 8 is configured to send a DL referencesignal, a control channel, a PCFICH, and a PHICH. The unicast of DLsubframe 7 and DL subframe 8 is configured to send a DL referencesignal.

In the frame structure according to the embodiment of the presentinvention, the original DL subframes for the UL or DL relay link mayalso be the MBSFN subframes in an LTE/LTE-A TDD system, and the unicastparts of the MBSFN subframes are configured to send the DL referencesignal and/or control signaling, such as a control channel, a PCFICH,and a PHICH. The rest of the time is used for the relay linktransmission between the RN and the eNB, and the GP. The method isapplicable in other cases with other ratios, which is not describedherein again.

In all of the above embodiments, the GP of the relay subframe includesthe GP of the DL relay subframe and the GP of the UL relay subframe. Forthe GP of the DL relay subframe, as shown by subframes 7 and 8 in FIG.7, when the transmission time (the idle time) is longer than thetransition time (the receive-transmit or the transmit-receive transitiontime of the RN), for the relay frame of the RN, for example, subframe 7of the Psubframe, the GP in the subframe is required to be divided intotwo parts: a GP RGPf before the Psubframe (a first part of a relay GP)and a GP RGPb after the Psubframe (a second part of the relay GP). TheGP RGPf before the Psubframe=the transmission time (the transmissiontime from the RN to the eNB, which is referred to as the transmissiontime for short hereinafter). The GP after the Psubframe=thetransmit-receive transition time of the RN (which is referred to as theRN transition time for short hereinafter). In FIG. 7, for relay subframe7 corresponding to the relay frame of the eNB, RGPf=0, RGPb=thetransmission time+the receive-transmit transition time of the RN (whichis referred to as the RN transition time for short hereinafter). In allof the above embodiments, the method for determining the GP is the samewhen the DL subframe is used as the relay subframe. When thetransmission time is shorter than the transition time, for relaysubframe 7 of the relay frame of the RN, RGPf=the RN transition time,and RGPb=the RN transition time. For relay subframe 7 corresponding tothe relay frame of the eNB, RGPf=0, RGPb=the RN transition time+the RNtransition time.

The GP of the UL relay subframe includes the GP of the DL subframe usedas the UL relay subframe and the GP of the UL subframe used as the ULrelay subframe. For the GP of the DL subframe used as the UL relaysubframe, for example, subframe 9 in FIG. 9, when the transmission timeis longer than the transition time, in subframe 9 of the RN relay frame,RGPf=the RN transition time, and RGPb=the transmission time; and insubframe 9 of the eNB relay frame, RGPf=the RN transition time+thetransmission time, and RGPb=0. When the transmission time is shorterthan the transition time, in subframe 9 of the RN relay frame, RGPf=theRN transition time, and RGPb=the transition time; and in subframe 9 ofthe eNB relay frame, RGPf=the RN transition time+the transmission time,and RGPb=the transition time−the transmission time. The GP of the ULsubframe used as the UL relay subframe is as shown by subframe 3 in FIG.7. When the transmission time is longer than the transition time, insubframe 3 of the RN relay frame, RGPf=the RN transition time, andRGPb=the transmission time; and in subframe 3 of the eNB relay frame,RGPf=the RN transition time+the transmission time, and RGPb=0. When thetransmission time is shorter than the transition time, in subframe 3 ofthe RN relay frame, RGPf=the RN transition time, and RGPb=the transitiontime; and in subframe 3 of the eNB relay frame, RGPf=the RN transitiontime+the transmission time, and RGPb=the transition time−thetransmission time.

The GP formed by one or more among the above transition time, thetransmission time, and the idle time may also be adjusted by atransmitter and a receiver in signaling, for example, regularly, and notindicated in the frame structure.

FIG. 16 is a schematic structural view of a communication apparatusaccording to an embodiment of the present invention. As shown in FIG.16, the communication apparatus includes a configuring module 151 and atransmitting module 152. The configuring module 151 is configured toconfigure a subframe of a TDD relay frame for a subframe of relay link.The configuring the subframe of the TDD relay frame for the subframe ofrelay link includes: configuring a DL subframe of the TDD relay framefor a DL subframe of relay link, and/or configuring the DL subframe ofthe TDD relay frame for a UL subframe of relay link, and/or configuringa UL subframe of the TDD relay frame for the UL subframe of relay link.The transmitting module 152 is configured to perform relay transmissionaccording to the subframe of relay link configured by the configuringmodule 151.

When the relay transmission is performed according to the configuredsubframe of relay link, if the DL subframe of the relay frame is used asthe UL subframe of relay link or the DL subframe of relay link, thefirst N OFDM symbols of the DL subframe are configured for access linktransmission between a RN and a UE under the RN or between an eNB and aUE under the eNB, and are configured to send a DL reference signal, or aDL reference signal and control signaling. Other OFDM symbols of the DLsubframe are used for relay link transmission and/or a GP; that is tosay, the time other than the first N OFDM symbols of the DL subframe isused for the relay link transmission and/or the GP, and may also be usedfor the access link transmission between the eNB and the UE under theeNB.

The DL subframe includes M OFDM symbols, M and N are natural numbers,and N is smaller than M.

The solution provided by the embodiment of the present invention can beapplied to systems such as LTE, LTE-A, all versions of the LTE (such asRel-8, Rel-9, and Rel-10), WiMax, and UWB.

Taking an LTE/LTE-A system for example, in the embodiment of the presentinvention, the configuring module 151 further includes a firstconfiguring unit 1511, a second configuring unit 1512, a thirdconfiguring unit 1513, a fourth configuring unit 1514, a fifthconfiguring unit 1515, and a sixth configuring unit 1516.

When a ratio of DL subframes to UL subframes is 6:3, the firstconfiguring unit 1511 is configured to configure subframe 3 for a ULsubframe of relay link, and configure subframes 7 and 8 for DL subframesof relay link; or, configure subframe 3 for the UL subframe of relaylink, and configure subframes 7 and 8 and subframe 9 for the DLsubframes of relay link; or, configure subframe 7 for the DL subframe ofrelay link, and configure subframe 9 for the UL subframe of relay link;or, configure subframe 7 for the UL subframe of relay link, andconfigure subframe 9 for the DL subframe of relay link; or, configuresubframe 7 for the DL subframe of relay link, and configure subframe 8for the UL subframe of relay link; or, configure subframe 7 for the ULsubframe of relay link, and configure subframe 8 for the DL subframe ofrelay link; or, configure one or more among subframes [3, 7, 8, 9] forthe DL subframes of relay link, and configure the rest subframes for theUL subframes of relay link. The number of the subframes that are used asthe UL subframes of relay link is greater than or equal to 1, andsubframe 3 can only be used as the UL subframe of relay link.

When the ratio of the DL subframes to the UL subframes is 3:1, thesecond configuring unit 1512 is configured to configure subframe 4 forthe DL subframe of relay link, and configure subframe 9 for the ULsubframe of relay link; or, configure subframe 4 for the UL subframe ofrelay link, and configure subframe 9 for the DL subframe of relay link;or, configure one or more among subframes [3, 4, 8, 9] for the DLsubframes of relay link, and configure the rest for the UL subframes ofrelay link. The number of the subframes that are used for the ULsubframes of relay link is greater than or equal to 1.

When the ratio of the DL subframes to the UL subframes is 7:2, the thirdconfiguring unit 1513 is configured to configure subframe 4 for the DLsubframe of relay link, and configure subframe 7 for the UL subframe ofrelay link; or, configure subframe 4 for the UL subframe of relay link,and configure subframe 7 for the DL subframe of relay link; or,configure one or more among subframes [4, 7, 8, 9] for the DL subframesof relay link, and configure the rest for the UL subframes of relaylink. The number of the subframes that are used as the UL subframes ofrelay link is greater than or equal to 1.

When the ratio of the DL subframes to the UL subframes is 2:2, thefourth configuring unit 1514 is configured to configure subframe 9 forthe DL subframe of relay link, and configure subframe 3 for the ULsubframe of relay link; or, configure subframe 4 for the DL subframe ofrelay link, and configure subframe 8 for the UL subframe of relay link;or, configure subframes 4 and 9 for the DL subframes of relay link, andconfigure subframes 3 and 8 for the UL subframes of relay link; or,configure one or more among subframes [3, 4, 8, 9] for the DL subframesof relay link, and configure the rest subframes for the UL subframes ofrelay link. The number of the subframes that are used as the ULsubframes of relay link is greater than or equal to 1, and subframes 3and 8 can only be used as the UL subframes of relay link.

When the ratio of the DL subframes to the UL subframes is 3:5, the fifthconfiguring unit 1515 is configured to configure subframe 9 for the DLsubframe of relay link, and configure subframe 4 for the UL subframe ofrelay link.

When the ratio of the DL subframes to the UL subframes is 8:1, the sixthconfiguring unit 1516 is configured to configure one or more amongsubframes [3, 4, 7, 8, 9] for the DL subframes of relay link, andconfigure the rest for the UL subframes of relay link. The number of thesubframes that are used as the UL subframes of relay link is greaterthan or equal to 1.

The communication apparatus in the embodiment of the present inventionis applicable to all of the methods of the above embodiments. In theembodiment of the present invention, when the communication apparatustransmits data, the subframe that can be used for the relay linktransmission is configured, data transmission performed by using therelay link complies with inherent constraints of the TDD frame structurein the prior art, and coverage of a system using the TDD relay frame isexpanded, thus improving the throughput.

Through the above description of the implementation, it is clear topersons skilled in the art that the present invention may beaccomplished through hardware, or through software plus a necessaryuniversal hardware platform. Base on this, the technical solutions ofthe present invention may be embodied in the form of a software product.The software product may be stored in a nonvolatile storage media (forexample, CD-ROM, USB flash drive, or removable hard disk) and containseveral instructions configured to instruct computer equipment (forexample, a personal computer, a server, or network equipment) to performthe method according to the embodiments of the present invention.

The above descriptions are merely some exemplary embodiments of thepresent invention. It should be noted by persons of ordinary skill inthe art that modifications and improvements may be made withoutdeparting from the principle of the present invention, which should beconstrued as falling within the scope of the present invention.

What is claimed is:
 1. A relay transmission method, comprising:performing, by a base station, transmission between the base station anda relay node (RN) on a relay link, the relay link comprising an uplink(UL) relay link from the RN to the base station and a downlink (DL)relay link from the base station to the RN; wherein a time divisionduplex (TDD) frame includes ten subframes that are labeled as 0 to 9from a first subframe to a tenth subframe, subframes 0, 4, 5 and 9 ofthe TDD frame being downlink subframes, subframes 2, 3, 7 and 8 of theTDD frame being uplink subframes, and subframes 1 and 6 of the TDD beingspecial subframes; and wherein subframe 9 of the TDD frame is configuredfor the DL relay link and subframe 3 of the TDD frame is configured forthe UL relay link; or, subframe 4 of the TDD frame is configured for theDL relay link and subframe 8 of the TDD frame is configured for the ULrelay link; or, subframes 4 and 9 of the TDD frame are configured forthe DL relay link and subframes 3 and 8 of the TDD frame are configuredfor the UL relay link.
 2. The method according to claim 1, wherein eachsubframe configured for the DL relay link includes M symbols, whereinfirst N symbols of each subframe that are configured for the DL relaylink being configured for access link transmission, and wherein M and Nare natural numbers and N is smaller than M.
 3. A base station,comprising: a transmitter configured to transmit data to a relay node(RN) on a downlink (DL) relay link, the DL relay link being from thebase station to the RN; and a receiver configured to receive data fromthe RN on an uplink (UL) relay link, the UL relay link being from the RNto the base station; wherein a time division duplex (TDD) frame includesten subframes that are labeled as 0 to 9 from a first subframe to atenth subframe, subframes 0, 4, 5 and 9 of the TDD frame being downlinksubframes, subframes 2, 3, 7 and 8 of the TDD frame being uplinksubframes, and subframes 1 and 6 of the TDD being special subframes; andwherein subframe 9 of the TDD frame is configured for the DL relay linkand subframe 3 of the TDD frame is configured for the UL relay link; or,subframe 4 of the TDD frame is configured for the DL relay link andsubframe 8 of the TDD frame is configured for the UL relay link; or,subframes 4 and 9 of the TDD frame are configured for the DL relay linkand subframes 3 and 8 of the TDD frame are configured for the UL relaylink.
 4. The base station according to claim 3, further comprising aprocessor configured to configure subframe 9 for the DL relay link andsubframe 3 for the UL relay link; or configure subframe 4 of the TDDframe for the DL relay link and subframe 8 of the TDD frame for the ULrelay link; or configure subframes 4 and 9 of the TDD frame for the DLrelay link and subframes 3 and 8 of the TDD frame for the UL relay link.5. The base station according to claim 3, wherein each subframeconfigured for the DL relay link includes M symbols, wherein first Nsymbols of each subframe that are configured for the DL relay link beingconfigured for access link transmission, and wherein M and N are naturalnumbers and N is smaller than M.
 6. A relay transmission method,comprising: performing, by a base station, transmission between the basestation and a relay node (RN) on a relay link, the relay link comprisingan uplink (UL) relay link from the RN to the base station and a downlink(DL) relay link from the base station to the RN; wherein a time divisionduplex (TDD) frame includes ten subframes that are labeled as 0 to 9from a first subframe to a tenth subframe, subframes 0, 5, 6, 7, 8 and 9of the TDD frame being downlink subframes, subframes 2, 3, and 4 of theTDD frame being uplink subframes, and subframe 1 of the TDD being aspecial subframe; and wherein subframes 7, 8 and 9 of the TDD frame areconfigured for the DL relay link and subframe 3 of the TDD frame isconfigured for the UL relay link.
 7. The method according to claim 6,wherein each subframe configured for the DL relay link includes Msymbols, wherein first N symbols of each subframe that are configuredfor the DL relay link being configured for access link transmission, andwherein M and N are natural numbers and N is smaller than M.
 8. A basestation, comprising: a transmitter configured to transmit data to arelay node (RN) on a downlink (DL) relay link, the DL relay link beingfrom the base station to the RN; and a receiver configured to receivedata from the RN on an uplink (UL) relay link, the UL relay link beingfrom the RN to the base station; wherein a time division duplex (TDD)frame includes ten subframes that are labeled as 0 to 9 from a firstsubframe to a tenth subframe, subframes 0, 5, 6, 7, 8 and 9 of the TDDframe being downlink subframes, subframes 2, 3, and 4 of the TDD framebeing uplink subframes, and subframe 1 of the TDD being a specialsubframe; and wherein subframes 7, 8 and 9 of the TDD frame areconfigured for the DL relay link and subframe 3 of the TDD frame isconfigured for the UL relay link.
 9. The base station according to claim8, further comprising a processor configured to configure subframes 7, 8and 9 of the TDD frame for the DL relay link and subframe 3 of the TDDframe for the UL relay link.
 10. The base station according to claim 8,wherein each subframe configured for the DL relay link includes Msymbols, wherein first N symbols of each subframe that are configuredfor the DL relay link being configured for access link transmission, andwherein M and N are natural numbers and N is smaller than M.